Non-severe hypoglycemia worsens cognitive function in type 2 diabetes
Denmark: Acute non-severe hypoglycaemia (mean plasma glucose 3.1 mmol/l) negatively impacts cognitive function in people with type 2 diabetes (T2D), according to a recent study published in the journal Diabetologia.
Previous studies have demonstrated a relationship between cognitive impairment and hypoglycaemia (<3 mmol/l).
This randomised crossover study involved 25 patients with type 2 diabetes who attended two experimental visits with hyperinsulinaemic glucose clamping: one hypoglycaemic clamp (plasma glucose 3.0 ± 0.2 mmol/l) and one euglycaemic clamp (plasma glucose 6.0 ± 0.2 mmol/l).
Participants were deemed eligible if their diabetes was treated with diet or glucose-lowering medications (except sulfonylureas or insulin), age was 35-70 years, BMI was 23-35 kg/m2 and HbA1c was below 75 mmol/mol (9%). cognitive function was assessed with a neurocognitive test battery measuring verbal memory, executive function, sustained attention and psychomotor speed.
A measurement for psychomotor speed was selected as the primary outcome. Participants and people assessing the outcomes were blinded to group assignment.
Key findings include:
- Cognitive performance was impaired during hypoglycaemia with a mean score in the primary outcome test, Symbol Digit Modalities Test measuring psychomotor speed, of 48.7 ± 9.8 (hypoglycaemia) vs 56.6 ± 12.0 (euglycaemia); i.e. a change of -7.9 points.
- In addition, hypoglycaemia reduced the global cognitive score by -0.7.
- A stable glucose plateau was achieved during both experimental visits.
- For the hypoglycaemic clamp, mean plasma glucose concentration (± SD) during neurocognitive testing was 3.1 (± 0.3) mmol/l.
- Age, sex, fasting C-peptide, counter-regulatory hormones and the severity of hypoglycaemic symptoms did not influence cognitive function.
"Acute non-severe hypoglycaemia (mean plasma glucose 3.1 mmol/l) has a substantial negative impact on cognitive function in individuals with type 2 diabetes," concluded the authors.
More information: Experimental non-severe hypoglycaemia substantially impairs cognitive function in type 2 diabetes: a randomised crossover trial published in journal Diabetologia.
Journal information: Diabetologia